1. Field of the Invention
This invention relates generally to fixtures for use in testing disk drives, and relates more particularly to an in-line, low-profile fixture clamp that is useful for quickly changing a head-mounting arm.
2. Description of the Relevant Art
Certification testing of magnetic-recording disk drives involves using a fixture to position a test head or other device relative to a rotating disk. Both disks and heads can be tested. A positioning device, typically a linear or rotary actuator of some sort, is used to move the head in a radial or arcuate path across the area of the disk that is of interest. During certification testing, a disk can be changed by removing the disk from a spindle and loading another disk onto the spindle. Changing a head is somewhat more complicated because of the precise alignment needed between the head and data tracks recorded on the disk.
Prior fixtures used in disk and head certification testing were difficult and time-consuming to use. If a head needed to be changed, a head-mounting structure had to be unbolted from its headblock, then removed and replaced with another head-mounting structure holding a replacement head. The subsequent realignment of the head relative to the disk data tracks often consumed a great deal of time. The head could be aligned with the headblock clamp loosened, but the head would move out of alignment once the clamp was tightened to lock the head-mounting structure in place. As a result, the prior fixtures did not provide an adequate means for quickly and easily changing a head mount. The prior fixtures also did not provide a convenient means for adjusting the height of the head relative to the disk surface, relying on shims that had to be individually inserted or removed to change the height.